1. Field of the Invention
The present invention relates to a recording medium for recording data streams. A title domain, menu domain and navigation information for control of reproduction of data streams are provided to control playback of a title from a preselected resume position.
2. Description of the Related Art
An optical disk is capable of storing video data with a high-quality picture and audio data with high-quality sound thereon. A digital versatile disk (DVD) is an example of such optical disk. An optical disk apparatus, such as a DVD player, is capable of reproducing data streams recorded on the DVD and is widely commercially available.
An exemplary embodiment of such an optical disk apparatus is illustrated in FIG. 1. The optical disk apparatus comprises an optical pickup 11, a video disk play (VDP) system 12, a processor 13 and a memory 14. The processor 13 controls the operation of the VDP system 12 in response to a user's request to play an optical disk 10 loaded in the apparatus. Recorded on the optical disk, (e.g., the DVD), are data streams of a title domain and menu domain. Navigation information for control of reproduction of the data streams are also recorded thereon.
Referring to FIG. 2, the navigation information includes program chain command table information (PGC_CMDTI), a plurality of pre-commands (PRE_CMD#1-PRE_CMD#i), a plurality of post-commands (POST_CMD#1-POST_CMD#j) and a plurality of cell commands (C_CMD#1-C_CMD#k), which are recorded and managed in a program chain command table (PGC_CMDT).
The program chain command table information PGC_CMDTI includes information PRE_CMD_Ns about the number of the pre-commands, information POST_CMD_Ns about the number of the post-commands and information C_CMD_Ns about the number of the cell commands. The title domain includes a plurality of titles, each of which has a plurality of system parameters SPRMs in which 24 information recording fields 0 to 23 SPRM0-SPRM23 are respectively assigned as shown in FIG. 3.
A title number for the title domain is recorded in the field 4 SPRM4. A video title set title program chain number for the title domain is recorded in the field 5 SPRM5. A title program chain number for the title domain is recorded in the field 6 SPRM6. A part-of-title number for one sequential program chain title is recorded in the field 7 SPRM7. A highlighted button number for a selection state is recorded in the field 8 SPRM8. The information recording fields 21 to 23 SPRM21-SPRM23 are reserved.
The optical disk apparatus performs a series of data reproduction operations corresponding to the user's request by searching for and referring to the navigation information recorded and managed in the above-mentioned manner. An optical disk system for recording data streams of a title domain with a main title and bonus video titles and data streams in a menu domain including a root menu is needed to support various contents, such as games. An efficient resume function for seeking and playing a predetermined position of a specific title when a playback operation is returned from the menu domain to the title domain is also needed.